1. Field of the Invention
The invention relates generally to gates, bridges, and movable barriers used to regulate vehicle and pedestrian traffic through a control locus. The invention particularly relates to barrier systems effective to disable even heavy transport vehicles that attempt to force entry through a controlled-access perimeter.
2. State of the Art
It is known to provide various forms of gates at control points of security perimeters to regulate traffic through a reduced number of entrances. Known gates include chain link fencing sections, wooden or metal cantilevered and raisable bars, and other generally light-weight obstruction devices. Such devices are typically light in weight to facilitate their operation, increase speed of actuation between open and closed positions, and to reduce associated wear and tear. Raisable bar type barriers are typically pivotally mounted at one end to permit their vertically pivoting removal from a blocking position. One known chain link gate is arranged for guillotine travel up and down. Often, a guard shack, or outbuilding is situated in proximity to the control locus to provide climate-controlled shelter to a person responsible for enforcing control of traffic at that location. Such known traffic-regulating arrangements can provide effective barriers to pedestrian access, but are insufficient to withstand an assault by determined individuals operating certain vehicles.
Rigorous control of access by vehicles to sensitive areas has become a significant problem in view of terrorist activities. One probable mode of attack by certain individuals desiring to cause damage to certain infrastructure includes using a loaded fuel-carrying tanker truck as a road-enabled bomb. Such vehicles are massive, and due to their inherent inertia, are difficult to force to a stop without the cooperation of the driver.
Various methodologies and devices have been employed in attempts to control travel of even large vehicles. Certain devices have been employed to control vehicle speed through a speed control area. Such devices include speed bumps and barriers placed to form a labyrinth path. Permanent speed bumps undesirably effect all traffic that passes over them, at all times. Therefore, smooth flow of traffic can sometimes be compromised. Speed bumps undesirably impose an annoyance on all drivers and passengers who travel over the speed control area. Speed bumps cause dirt, snow, and other debris carried by vehicles to fall from the vehicles as they pass over and are jostled by the bumps, thereby undesirably littering the area near the speed bumps. Furthermore, such bumps may suffer wear and tear from heavy vehicles, requiring excessive repair and maintenance.
The serpentine path required to negotiate a labyrinth path can be effective to reduce speed of a vehicle through a control area. In an effective labyrinth path, drivers are required to manipulate their vehicles through convolutions and sharp turns. Unavoidably, certain vehicles will fail to successfully negotiate one or more turns, running into portions of barriers, and causing unwanted damage to vehicles. In any event, speed control structures such as bumps and labyrinth paths do not provide a sure stopping capability to provide full control over vehicle access beyond a control point.
It is known to place physical barriers across a roadway to ensure vehicles come to a complete stop at a control point. Certain barriers are inadequate to force large vehicles to come to a stop. For example, a chain link fence gate is generally deemed too flimsy to significantly impede the forward progress of a heavy cargo-laden vehicle, such as a loaded tanker truck. Similarly, pivotally mounted, cantilevered bar-type obstructions, such as those lowered to block a highway at certain rail road crossings, also lack sufficient stopping power to impede progress of a vehicle driven by an uncooperative driver.
Massive barriers, such as certain barriers made from sections of concrete, are known as effective tools to resist forward progress of even large 18-wheel-type vehicles. One such concrete barrier is commonly known as a “Jersey Barricade”, and has been placed in service in traffic situations throughout the United States for a sufficient amount of time to be generally recognized by many motorists, simply by its shape and overall appearance.
Conventionally, the Jersey Barricade is formed from molded concrete, and has a plain, unadorned, generally pyramidal cross-section. Sometimes, one or more loops of rebar are arranged to protrude from the top and may serve as pick-up points for a crane or other piece of heavy equipment to move the barricade. A typical use for such Jersey Barricades is in end-to-end alignment to form temporary lanes in which to confine vehicle travel near road construction sites. Such massive concrete barriers are effective to disable even large cargo-carrying vehicles that might attempt to travel through, rather than parallel to, a line of such barricades. However, a pedestrian can simply jump over a conventional Jersey Barricade.
A known method to place such Jersey Barricades includes tedious use of a forklift, crane, or other large piece of machinery to individually place sections of the barricade in a desired position. Such placement requires specialized machinery, which may not be available at certain locations at which it is desired to impose control of vehicle access. Placement of barrier sections one-at-a-time can undesirably consume a significant amount of time, and is inconvenient. Furthermore, when it is desired to permit vehicle progress beyond the control point, the barrier sections must be moved out of the way. Therefore, it would be an improvement to provide a more convenient barrier arrangement effective to reliably enforce control of vehicle access through a control locus. It would be a further improvement for the improved barrier to additionally provide control of pedestrian travel through the control locus.